So I have a problem when I tune my guitar down to say D standard. Say if I'm putting my E to D I will go to the A and it will be a little closer to the A# then I left it and if I tune that down G the other strings will just keep going higher; if I don't tend to them and well I've had the High E, B and G snap from this happening and it's really annoying because my other guitar doesn't do it but this one is better.
A similar question to this was asked over the last couple of weeks. I guess the guitar has a vibrato. In this case, as the strings are loosened, it makes the springs in the vibrato relatively stronger, thus they pull the remaining strings tighter, and so, higher in pitch.This is a phenomenon associated with vibratos (trems), and is basically the nature of the beast. It's very unusual for this to result in broken strings, though.
Check how many springs are fitted inside the guitar body - in your case 2 or 3 will be enough.
You probably need to take it to a shop, or guitar tech, as there may be other factors that need adjustment - action, truss rod are two.
If your guitar is not vib-equipped, this answer will be of no help at all...
Tremolo systems are a balancing act between strings and springs, especially if you've set it so it goes down and up. Eddie Van Halen, for example, has his Floyd Rose set to only go down, so (among other things) he can use a Drop-D add-on without throwing the whole setup out of balance.
To recap and reiterate: If you're rocking a whammy-bar guitar, look into having a guitar for each tuning, or a hardtail guitar for changing tunings and keeping your tremolo-having guitar in one tuning.
I'd guess getting to the point of snapping points to other bridge issues, too, but maybe not.
This is common for all guitars, with and without a tremolo, in my experience. I have noticed this happen on my acoustic and two different electrics. The guitar's neck is angled so the tension of the strings, when in tune, will cause it to assume the correct shape. Without strings, the neck will relax and be straighter/longer than it would be when strung. The effect of this is when you put on nothing but the thinnest-gauge strings, they are under more tension and require less winding to bring up to pitch. If you string a guitar high-to-low, you will find that as you add lower strings you will continually have to raise the higher pitched strings back into tune (as they get flattened when the low strings relieve some of their tension by pulling on the neck).
I recommend always detuning starting with the highest-pitched strings first, and stringing a guitar in the order E-G-A-B-D-E to alleviate these issues.